Earth-working machines, such as cable shovels, excavators, wheel loaders, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earthen material. These implements are subjected to extreme abrasion and impacts that cause them to wear. To prolong the useful life of the implements, various ground engaging tools can be connected to the earth-working implements at areas experiencing the most wear. These ground engaging tools are replaceably connected to the implements using a retention system.
An exemplary retention system is disclosed in U.S. Pat. No. 8,458,931 of Knight that issued on Jun. 11, 2013 (“the '931 patent”). Specifically, the '931 patent discloses a fork-shaped tool body that fits over the front edge of an excavator bucket. A clamp passes through the body and the bucket, and a wedge is inserted alongside the clamp to hold the clamp in position. The wedge has a U-shaped axial recess, and a threaded rod is received within the recess and oriented at an angle relative to the clamp. A threaded block is mounted to the rod, and the rod is rotatable to move the block along the rod. The block includes teeth that engage the clamp upon insertion of the wedge into the body, such that as the rod is rotated and the block moves along the rod, the wedge is forced further into the body. As the wedge is forced further into the body, the clamp is urged tighter against the body and the bucket. With this configuration, the fork-shaped tool body can be removably connected to the excavator bucket by rotation of the rod.
Although acceptable for some applications, the retention system of the '931 patent may be less than optimal. In particular, the retention system may be limited in travel by a length of the rod and clearances required inside the system for assembly purposes. Specifically, in order to engage the teeth of the block with the teeth of the clamp, peaks of the block teeth must first pass over peaks of the wedge teeth during wedge insertion. When this happens, the wedge is forced away from the clamp. The extra clearance consumed by the wedge at this time must first be taken up by rotation of the rod, before the rod rotation functions to tighten the system. In some embodiments, this may leave little rod rotation remaining for use in tightening the system. In addition, during removal of the wedge, the block teeth may remain engaged with the clamp teeth even after the rod has been rotated in a loosening direction, making subsequent removal of the wedge difficult.
Another exemplary retention system is disclosed in U.S. Patent Application 2015/0197921 of Campomanes that published on Jul. 16, 2015 (“the '921 publication”). In this retention system, a pocket is formed at an end of a wedge channel. The pocket is an inclined area of increased depth that is configured to receive a corresponding slider block as the slider block is moved deeper into the wedge. This may allow teeth of the slider block to drop out of meshed engagement, which may be helpful during assembly. In addition, it may allow the wedge to be inserted a greater distance before engagement with the clamp occurs, thereby providing for an enhanced connection.
While the pocket of the '921 publication may result in easier assembly and an improved connection, it may still be less than optimal. In particular, the slider block may still be pulled by gravity into premature connection with the clamp during assembly. Additionally, gravity may inhibit the slider block from disengaging from the clamp during disassembly, even though clearance may be available in the pocket.
The disclosed tool retention system and wedge are directed to overcoming one or more of the problems set forth above.